An investigation to relate the overall size of the maxillary arch and the area of palatal mucosa in cleft lip and palate cases at birth to the overall size of the upper dental arch at five years of age.

The area of palatal mucosa and the size of the maxillary arches were measured in a group of 30 newborn infants with unilateral clefts of the lip and palate. The overall size of the maxillary arch together with the arch width and arch height were also measured when the children had reached 5 years of age. For comparison purposes, a group of 30 newborn normal children and 30 normal 5-year-old children were similarly measured. The cleft children were found to have a mean deficiency of palatal mucosa of 16.41% at birth, although the overall size of their maxillary arches was 17.08% greater than normal. In the cleft cases there was no significant correlation between the area of palatal mucosa at birth and the overall size of the arch at 5 years of age. A significant correlation did exist between the overall size of the arch at birth and the overall size when the child was 5 years old. The significance of this and other findings is discussed.